Page 98 - Cardiac abnormalities after aneurysmal subarachnoid hemorrhage

Chapter 7
acute phase there may be an altered- or loss of consciousness, nausea or vomiting. Coma and seizures are associated with poor outcome. The annual incidence of aSAH adjusted for age and sex, is 7.5-12.9 per 100,000 population per year. This devastating neurological disorder accounts for 22-25% of cerebrovascular deaths1. Improvement of medical treatment has led to an improvement of outcome in patients with aSAH2, although the mainstay of treatment remains obliteration of the aneurysm. Postoperative care is based on optimizing cerebral oxygenation, which is dependent on oxygenation of blood, oxygen transport capacity of the blood, and cerebral perfusion. A common complication with a negative impact on outcome is delayed cerebral ischemia (DCI) which usually occurs 4-7 days after the aSAH. This may be caused by multiple factors among which are vasospasm and hydrocephalus. Cerebral perfusion may be influenced by a number of other factors, among which, importantly, are cardiac output and blood pressure. The cardiac abnormalities after aSAH are sometimes accompanied by a drop in cardiac output and blood pressure, hence influencing patients’ condition and neurological outcome unfavorable. In Chapter 2 of this thesis we describe the results of our meta-analysis on the literature. We found that reported incidence varies widely. Furthermore, we found that cardiac abnormalities may be associated with poor outcome independent of other clinical variables. However, due to the limitation of the studies, no definitive conclusions could be made. We therefore launched the consecutive and prospective cohort study Serial Echocardiography After SubArachnoid Hemorrhage (SEASAH). The results of SEASAH are described in Chapter 3 and Chapter 4. Most literature focuses on electrocardiographic abnormalities and/or echocardiographic abnormalities and/or biochemical changes. We analyzed and describe these cardiac investigations separately, although they all reflect on the same disease.
Electrocardiographic Changes and Cardiac Arrhythmia’s
The first report of neurogenic electrocardiographic changes following a Central Nervous System (CNS) event occurred in 1938 when Aschenbrenner and Bodechtel3 stated that intracranial lesions may be responsible for ECG changes. Byer4 et al, in 1947, and Burch5 et al in 1954, found that these ECG abnormalities occur frequently in association with SAH. Since then, the majority of studies focused on ECG changes in aSAH. However, several other acute CNS events have also been reported to cause such abnormalities.6-20
The frequency of ECG changes in association with SAH ranges between 50% and 90%21-25. This large interval may largely be explained by the different monitoring
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